Do I need a check valve

[Diego]

Pulled the Emissions last night with a local VR4 guy, and he was talking about needing a check valve in the trunk or some business like that...

Can someone clue me in?


Thanks guys

Diego

 

[SouthCaliVR4]

Because you now have an open vent that could leak fuel a check valve/roll over valve is a good safety call.

 

[CutlassJim]

Look up how the emissions system works. Maybe a good idea before you start pulling stuff.

 

[Diego]

Jim, I've done some reading and its all here or there.

I realize that we have a filter on the tank, and that my Aero FPR has a ball and seat.
I also realize that the check valve is for something like a roll over so gas doesn't go spewing out when rolled....

Since we have a vent to the tank attached to the filler neck wouldn't we be all good?

 

[CutlassJim]

The rollover valve let's the gasoline fumes travel from the tank to the charcoal canister where when the valve there opens they get sucked into the intake manifold. It also closes if fluid hits it (rollover). It's the blue bodied valve that you move out of the way when installing a fuel pump. If you leave the 1/4" line that comes from the tank to the charcoal canister open it will let the fumes into your engine bay (bad) and the atmosphere (also bad) And you can't plug it or the fuel tank will pressurize with the expanding vapors.


So to answer your question you already have a rollover valve installed but you need to disconnect the outlet so it doesn't fill your engine bay with gasoline fumes.

 

[Diego]

So pull the blue filter/valve on the tank or just install a check valve on the FPR? How should it be done Jim?